Biotite Granite

Gray to white, medium-grained, massive to layered granite and granite gneiss range in composition from granite to quartz diorite. Quartz diorite dikes and sills are locally abundant. Mineralogy: quartz + potassium feldspar + plagioclase + biotite + epidote + muscovite ± clinopyroxene + hornblende. This unit intrudes biotite gneiss unit (Cbg).
State Virginia
Name Biotite Granite
Geologic age Proterozoic
Lithologic constituents
Major
Igneous > Plutonic > Granitic > Granitebiotite granite
Comments Central Virginia Volcanic-Plutonic Belt
References

Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000.

Virginia Division of Mineral Resources, 2003, Digital Representation of the 1993 Geologic Map of Virginia, Publication 174, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, scale 1:500,000.

NGMDB product
Counties Charlotte - Cumberland - Goochland - Halifax